Answer:
My seas have no water, my mountains have no rock, and my land has no grass. What am I?
I am a creature with a βtightβ name.
I am a kind of coat that can only be put on when wet.
I have no voice but I can teach you all there is to know. I have spines and hinges but I am not a door. Once I've told you all, I cannot tell you more. What am I?
I can be heard in a court or carried with you.
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.